humans Ancient DNA Reveals When Humans and Neanderthals Interbred 3 weeks ago Neanderthals and humans likely mixed and mingled during a narrow time frame 45,000 years ago, scientists reported Thursday. Researchers analyzed… Two Significant Life Events cause Humans to age Substantially: Research 5 months ago Researchers have discovered that humans age at the molecular level in two faster bursts, one around age 44 and the… Global Carbon dioxide levels at highest since evolution of humans, 415.26 parts per million 6 years ago Scientists in the United States have detected the most elevated amounts of planet-warming carbon dioxide in Earth's atmosphere since records…